package com.wjm.blog.common.util;

import cn.hutool.core.convert.Convert;
import cn.hutool.core.util.CharsetUtil;
import cn.hutool.core.util.ObjectUtil;
import cn.hutool.core.util.StrUtil;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

/**
 * 客户端工具类
 *
 * @author wang.shouyan
 */
public class ServletUtils {

    /**
     * 获取String参数
     */
    public static String getParameter(String name) {
        HttpServletRequest httpServletRequest = getRequest();
        if (ObjectUtil.isEmpty(httpServletRequest)) {
            return null;
        } else {
            return httpServletRequest.getParameter(name);
        }
    }

    /**
     * 设置String参数
     */
    public static void setAttribute(String name, Object value) {
        HttpServletRequest httpServletRequest = getRequest();
        if (ObjectUtil.isNotEmpty(httpServletRequest)) {
            httpServletRequest.setAttribute(name, value);
        } else {
            ThreadLocalUtils.set(name, value);
        }

    }

    /**
     * 设置String参数
     */
    public static Object getAttribute(String name) {
        HttpServletRequest httpServletRequest = getRequest();
        if (ObjectUtil.isEmpty(httpServletRequest)) {
            return ThreadLocalUtils.get(name);
        } else {
            return httpServletRequest.getAttribute(name);
        }
    }

    /**
     * 获取String参数
     */
    public static String getHeader(String name) {
        HttpServletRequest httpServletRequest = getRequest();
        if (ObjectUtil.isEmpty(httpServletRequest)) {
            return null;
        } else {
            return httpServletRequest.getHeader(name);
        }
    }

    /**
     * 获取String参数
     */
    public static String getParameter(String name, String defaultValue) {
        return Convert.toStr(getRequest().getParameter(name), defaultValue);
    }

    /**
     * 获取Integer参数
     */
    public static Integer getParameterToInt(String name) {
        return Convert.toInt(getRequest().getParameter(name));
    }

    /**
     * 获取Integer参数
     */
    public static Integer getParameterToInt(String name, Integer defaultValue) {
        return Convert.toInt(getRequest().getParameter(name), defaultValue);
    }

    /**
     * 获取request
     */
    public static HttpServletRequest getRequest() {
        ServletRequestAttributes servletRequestAttributes = getRequestAttributes();
        if (ObjectUtil.isEmpty(servletRequestAttributes)) {
            return null;
        } else {
            return servletRequestAttributes.getRequest();
        }
    }

    /**
     * 获取response
     */
    public static HttpServletResponse getResponse() {
        return getRequestAttributes().getResponse();
    }

    /**
     * 获取session
     */
    public static HttpSession getSession() {
        return getRequest().getSession();
    }

    public static ServletRequestAttributes getRequestAttributes() {
        RequestAttributes attributes = RequestContextHolder.getRequestAttributes();
        return (ServletRequestAttributes) attributes;
    }

    /**
     * 将字符串渲染到客户端
     *
     * @param response 渲染对象
     * @param string   待渲染的字符串
     * @return null
     */
    public static String renderString(HttpServletResponse response, String string) {
        try {
            response.setStatus(200);
            response.setContentType("application/json");
            response.setCharacterEncoding("utf-8");
            response.getWriter().print(string);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 是否是Ajax异步请求
     *
     * @param request
     */
    public static boolean isAjaxRequest(HttpServletRequest request) {
        String accept = request.getHeader("accept");
        if (accept != null && accept.indexOf("application/json") != -1) {
            return true;
        }

        String xRequestedWith = request.getHeader("X-Requested-With");
        if (xRequestedWith != null && xRequestedWith.indexOf("XMLHttpRequest") != -1) {
            return true;
        }

        String uri = request.getRequestURI();
        if (StrUtil.containsAnyIgnoreCase(uri, ".json", ".xml")) {
            return true;
        }

        String ajax = request.getParameter("__ajax");
        if (StrUtil.containsAnyIgnoreCase(ajax, "json", "xml")) {
            return true;
        }
        return false;
    }

    /**
     * 获取 request 请求体
     *
     * @param servletInputStream servletInputStream
     * @return body
     * @throws IOException
     */
    public static String getRequestBody(ServletInputStream servletInputStream) {
        StringBuilder sb = new StringBuilder();
        BufferedReader reader = null;
        try {
            reader = new BufferedReader(new InputStreamReader(servletInputStream, CharsetUtil.UTF_8));
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (servletInputStream != null) {
                try {
                    servletInputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return sb.toString();
    }
}
